Synthesis of 6-(het) ary Xylocydine analogues and evaluating their inhibitory activities of CDK1 and CDK2 in vitro

A series of purine nucleoside analogues bearing an aryl and hetaryl group in position 6 were prepared and their biological activities were assessed by in vitro CDK1/Cyclin B1 and CDK2/Cyclin A2 kinase assay. From the synthesized chemicals, three Xylocydine derivatives 3h, 3i, and 3j exhibited specific inhibitory activities on CDK2/Cyclin A2 with IC(50) values of 4.6, 4.8, and 55 μM, respectively. Those three compounds all induced G1/S phase arrest in Human epithelial carcinoma cell line (HeLa), and the results suggested they may inhibit CDK2 activity in vitro. Furthermore, molecular modeling study, their docking into Cyclin Dependant Kinase 2 (CDK2) active site showed high docking scores. Taken together, these data suggest that, those three compounds are good inhibitors of CDK2 for studying this kinase signal transduction pathway in cell system.     

Inhibin/activin-betaE subunit in normal and malignant human cervical tissue and cervical cancer cell lines

Inhibins are dimeric glycoproteins, composed of an alpha-subunit and one of two possible beta-subunits (betaA or betaB), with substantial roles in human reproduction and in endocrine-responsive tumours. Recently a novel beta subunit named betaE was described, although it is still unclear if normal or cancerous cervical epithelial cells as well as cervical cancer cell lines can synthesise the novel inhibin-betaE subunit. About 4 normal cervical tissue samples together with 10 specimens of well-differentiated squamous cervical cancer and adenocarcinoma of the cervix were immunohistochemical analyzed. Additionally, two cervical carcinoma cell lines (HeLa and CaSki) were analyzed by immunofluorescence and RT–PCR for the expression of this novel subunit. We demonstrated for the first time an immunolabelling of the inhibin-betaE subunit in normal and malignant cervical tissue, as well as cervical cancer cells. Although the physiological role is still quite unclear in cervical tissue, inhibin-βE might play important roles in carcinogenesis. Moreover, the synthesis of this subunit in cervical carcinoma cell lines of squamous and glandular epithelial origins also allows the use of these cell lines in elucidating its functions in cervical cancer pathogenesis. However, since the expression of the inhibin-βE is minimal in HeLa cells as assessed by immunofluorescence and RT–PCR, the CaSki cell line might be a better model for further functional experiments regarding cervical cancer pathogenesis.     

Lixazinone stimulates mitogenesis of Madin-Darby canine kidney cells

Polycystic kidney diseases (PKD) are characterized by excessive proliferation of renal tubular epithelial cells, development of fluid-filled cysts, and progressive renal insufficiency. cAMP inhibits proliferation of normal renal tubular epithelial cells but stimulates proliferation of renal tubular epithelial cells derived from patients with PKD. Madin-Darby canine kidney (MDCK) epithelial cells, which are widely used as an in vitro model of cystogenesis, also proliferate in response to cAMP. Intracellular cAMP levels are tightly regulated by phosphodiesterases (PDE). Isoform-specific PDE inhibitors have been developed as therapeutic agents to regulate signaling pathways directed by cAMP. In other renal cell types, we have previously demonstrated that cAMP is hydrolyzed by PDE3 and PDE4, but only PDE3 inhibitors suppress proliferation by inhibiting Raf-1 activity (Cheng J, Thompson MA, Walker HJ, Gray CE, Diaz Encarnacion MM, Warner GM, Grande JP. Am J Physiol Renal Physiol 287:F940-F953, 2004.) A potential role for PDE isoform(s) in cAMP-mediated proliferation of MDCK cells has not previously been established. Similar to what we have previously found in several other renal cell types, cAMP hydrolysis in MDCK cells is directed primarily by PDE4 (85% of total activity) and PDE3 (15% of total activity). PDE4 inhibitors are more effective than PDE3 inhibitors in increasing intracellular cAMP levels in MDCK cells. However, only PDE3 inhibitors, and not PDE4 inhibitors, stimulate mitogenesis of MDCK cells. PDE3 but not PDE4 inhibitors activate B-Raf but not Raf-1, as assessed by an in vitro kinase assay. PDE3 but not PDE4 inhibitors activate the ERK pathway and activate cyclins D and E, as assessed by histone H1 kinase assay. We conclude that mitogenesis of MDCK cells is regulated by a functionally compartmentalized intracellular cAMP pool directed by PDE3. Pharmacologic agents that stimulate PDE3 activity may provide the basis for new therapies directed toward reducing cystogenesis in patients with PKD.     

A review of in vitro modelling approaches to the identification and modulation of squamous metaplasia in the human tracheobronchial epithelium

Squamous metaplasia in the tracheobronchial epithelium (TBE) involves the replacement of the normal pseudostratified mucociliary epithelium with a stratified squamous epithelium. Squamous metaplasia is considered to be an adaptive response that protects the lumen from the effects of inhaled airborne pollutants, but which might also feature as a pre-neoplastic lesion preceding squamous cell carcinoma. With the exception of transglutaminase I, involucrin, and cytokeratins 5, 6 and 13, few markers that contribute to the squamous phenotype have been identified in human TBE that can be used in diagnosis or to monitor its development in laboratory investigations, and current models are inadequate to provide statistically meaningful data. Therefore, new predictive markers have been identified, and new techniques established, in epithelial in vitro models capable of expressing squamous characteristics, which will be used to identify hazardous exposures and elucidate the mechanisms by which they induce their effects. A protocol for the quantitative detection of transglutaminase activity has been standardised in keratinocytes, based on the enzymatic incorporation of fluorescein-cadaverine (FC) into bis(gamma-glutamyl) polyamine cross-links. The specificity of this compound as a transglutaminase substrate was demonstrated by using a range of competitive transglutaminase inhibitors, and by modulation of the squamous pathway. FC incorporation was localised to the cell membrane of terminally differentiating cells, and was not visible in basal, proliferating cells. High calcium-containing medium, nicotine and cigarette smoke condensates (CSC) induced an increase in FC incorporation, providing evidence of their role in enhancing the squamous pathway. Analysis by flow cytometry was used to provide a quantitative assessment of a range of optimised squamous differentiation markers, identified in normal human bronchial epithelia and in a bronchial cell line. Transglutaminase I was induced in a time-dependent manner, in post-confluent cells induced to differentiate down the squamous pathway, whereas involucrin was ubiquitously expressed and the levels of cytokeratins 5, 6 and 18 were reduced. The response of these and other differentiation markers to squamous-inducing conditions is being explored.     

New androst-4-en-17-spiro-1,3,2-oxathiaphospholanes. Synthesis, assignment of absolute configuration and in vitro cytotoxic and antimicrobial activities

The reactions of 17α-hydroxyprogesterone with Lawesson's reagent (LR) in toluene, CH(2)Cl(2) and/or CCl(4) gave, depending on the duration of the reaction, two diastereoisomeric androst-4-en-17-spiro-1,3,2-oxathiaphospholane-2-sulfide pairs 2a,b and 3a,b in approximately 7:3 ratio, differing in configuration at the phosphorus atom. A parallel analysis of heteronuclear 2D (1)H-(13)C spectra (HSQC and HMBC) and homonuclear 2D spectra (NOESY) enabled complete (1)H and (13)C assignments of each isomer. Also, analysis of NOESY correlations provided evidence for the preferred conformation. X-ray analysis of 3a confirmed the structure and absolute configuration on phosphorus. A pathway for the formation of 1,3,2-oxathiaphospholane ring was proposed. Cytotoxic activity in vitro was tested against three tumor cell lines (human cervix carcinoma HeLa cells and two human breast carcinoma MDA-MB-361 and MDA-MB-453 cells). Compound 3a and mixture 3a,b showed a moderate activity against HeLa and MDA-MB-453 cell lines while against MDA-MB-361 cell line all tested compounds exerted very weak cytotoxic effect. Antimicrobial activity against Gram-positive, Gram-negative bacteria and fungal cells, toxicity to brine shrimp Artemia salina, were evaluated. All tested compounds showed strong antifungal activity.     

The synthesis and biological evaluation of nucleobases/tetrazole hybrid compounds: A new class of phosphodiesterase type 3 (PDE3) inhibitors

Spired by the chemical structure of Cilostazol, a selective phosphodiesterase 3A (PDE3A) inhibitor, several novel hybrid compounds of nucleobases (uracil, 6-azauracil, 2-thiuracil, adenine, guanine, theophylline and theobromine) and tetrazole were designed and successfully synthesized and their inhibitory effects on PDE3A as well as their cytotoxicity on HeLa and MCF-7 cancerous cell lines were studied. Obtained results show the linear correlation between the inhibitory effect of synthesized compounds and their cytotoxicity. In some cases, the PDE3A inhibitory effects of synthesized compounds are higher than the Cilostazol. Besides, compared to a standard anticancer drug methotrexate, some of the synthesized compounds showed the higher cytotoxicity against the HeLa and MCF-7 cancerous cell lines.     

Cellular and molecular mechanisms of silibinin induces cell-cycle arrest and apoptosis on HeLa cells

Silibinin, an effective anti-cancer and chemopreventive agent in various epithelial cancer models, has been reported to inhibit cancer cell growth through mitogenic signalling pathways including cervical cancer. However, the underlying mechanisms are still not well elucidated. Here, we assessed the effect of silibinin on human cervical carcinoma cell cycle modulation, apoptosis induction and associated molecular alterations by employing HeLa cell line. Silibinin treatment of HeLa cells resulted in a G2 arrest and induced a decrease in cyclin-dependent kinases involved in both G1 and G2 progression. In addition, silibinin showed a dose-dependent and a time-dependent apoptotic death in HeLa cells in both the mitochondrial pathway and the death receptor-mediated pathway, providing a strong rationale for future studies evaluating preventive and/or intervention strategies for silibinin in cervical cancer pre-clinical models.     

Synthesis,anticancer, structural,and computational docking studies of 3-benzylchroman-4-one derivatives

A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC₅₀?=?20.1?µM) and 3h against HeLa cells (IC₅₀?=?20.45?µM). 3b also exhibited moderate activity against HeLa cells (IC₅₀?=?42.8?µM). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.     

Characterization of a cell line (SW756) derived from a human squamous carcinoma of the uterine cervix

Summary An established cell line, SW756, derived from a primary squamous carcinoma of the uterine cervix is described by its morphology, ultrastructure, karyotype, genetic signature analysis, HLA typing, and tumorigenesis in the nude mouse. Cultured cells obtained from the SW756 derived nude mouse tumor also were studied for chromosome and isozyme markers. The original tumor was poorly differentiated carcinoma with minimal keratinization and is compared with that occurring in the nude mouse after the cultured cells were inoculated. The nude mouse tumor showed similar histological features, but better differentiation than the original tumor. Karyotype analysis of SW756 demonstrated a hyperdiploid stem line number and several marker chromosomes (MI-M6). No HeLa marker chromosomes were identified. The isozyme pattern for SW756 reported by others has been confirmed. The unique chromosome and isozyme features have been identified repeatedly in the cultured cells and, most importantly, in the post nude mouse culture. We recommend SW756 as a defined human tumorigenic cell line derived from a primary squamous carcinoma of the uterine cervix. This investigation was supported in part by Public Health Research Grant CA-06294 from the National Cancer Institute, Department of Health and Human Services.     

GRP78在食管鳞状细胞癌、不典型增生及正常食管鳞状上皮组织中的表达

目的：检测葡萄糖调节蛋白78（glucose—regulated proteins78,GRP78）在同一食管癌患者食管的鳞状细胞癌、不典型增生及正常鳞状上皮组织中的表达,研究GRP78与食管鳞状细胞癌发生发展的关系。方法：取90例食管鳞状细胞癌患者的病变组织,其病理切片中正常鳞状上皮组织、不典型增生组织和鳞状细胞癌组织均存在,用免疫组化的方法,检测GRP78在3种不同组织中表达的情况,分析G史P78与性别、年龄、浸润深度、分化程度、分期及淋巴结转移等参数之间的关系。结果：GRP78在食管正常鳞状上皮组织、不典型增生组织、鳞状细胞癌组织中的阳性表达率分别为7．8％、85．6％、47．8％,GRP78在正常食管组织、不典型增生组织、食管鳞癌组织3组中表达的差异有显著性意义（P〈0．01）。鳞状细胞癌组织中GRP78表达阴性者,年龄较阳性者大;GRP78表达与肿瘤分化程度、分期、淋巴结转移等有明显相关性。结论：GRP78在食管正常细胞向恶性细胞转化的过程中可能扮演了重要角色,检测GRP78的表达可能有助于对食管鳞状细胞癌的预防及早期诊断。     

双向凝胶电泳-飞行时间质谱技术鉴定食管上皮细胞癌变时14-3-3 protein ε、S100A9的表达

[摘要] 目的：分析食管鳞癌和正常食管上皮细胞蛋白质的表达差异,获取鉴别两者的分子标志物。方法：通过激光捕获显微切割技术分离ESCC肿瘤细胞和癌旁上皮细胞,通过双向电泳和质谱技术鉴定表达异常的蛋白,并通过蛋白免疫印记证实部分差异蛋白的表达。结果：建立了食管癌组织和正常食管上皮蛋白的双向凝胶电泳图谱,通过质谱技术鉴定出14-3-3 protein ε、S100A9等蛋白在食管癌变时差异表达,蛋白印记结果证实14-3-3 protein ε、S100A9的表达量在食管癌变时分别上调和下调。结论：激光捕获显微切割是蛋白质组研究中的一个突破性的技术,可以有效地解决组织异质性的问题;本实验检测到的差异蛋白例如14-3-3 protein ε、S100A9可能成为鉴别食管癌组织和正常食管上皮特异性的分子标记物。     

Fragment-based screening for inhibitors of PDE4A using enthalpy arrays and X-ray crystallography

Fragment-based screening has typically relied on X-ray or nuclear magnetic resonance methods to identify low-affinity ligands that bind to therapeutic targets. These techniques are expensive in terms of material and time, so it useful to have a higher throughput method to reliably prescreen a fragment library to identify a subset of compounds for structural analysis. Calorimetry provides a label-free method to assay binding and enzymatic activity that is unaffected by the spectroscopic properties of the sample. Conventional microcalorimetry is hampered by requiring large quantities of reagents and long measurement times. Nanocalorimeters can overcome these limitations of conventional isothermal titration calorimetry. Here we have used enthalpy arrays, which are arrays of nanocalorimeters, to perform an enzyme activity-based fragment screen for competitive inhibitors of phosphodiesterase 4A (PDE4A). Several inhibitors with K ( I ) <2 mM were identified and moved to X-ray crystallization trials. Although the co-crystals did not yield high-resolution data, evidence of binding was observed, and the chemical structures of the hits were consistent with motifs of known PDE4 inhibitors. This study shows how array calorimetry can be used as a prescreening method for fragment-based lead discovery with enzyme targets and provides a list of candidate fragments for inhibition of PDE4A.     

Preparation of a Novel Organoselenium Compound and Its Anticancer Effects on Cervical Cancer Cell Line HeLa

This study aims at developing new organoselenium compounds with good anticancer ability and low biotoxicity. Sucrose selenious ester (sucrose-Se) was synthesized by the reaction between sucrose and selenium oxychloride. MTT assay showed that sucrose-Se effectively inhibited the proliferation of cervical cancer cell line HeLa in a dose-dependent manner without cytostatic influence on human normal liver cell line HL-7702. Morphological observation and agarose gel electrophoresis demonstrated that sucrose-Se induced apoptosis to HeLa cells. In addition, sucrose-Se was able to inhibit proliferation of bladder carcinoma cell line 5637, human malignant melanoma cell line A375, and gastric carcinoma cell line MGC-803. Median lethal dose of sucrose-Se and sodium selenite was 290.0 and 13.1 ppm, respectively, in the acute toxicity test on mice. In conclusion, sucrose-Se has potential in cancer chemoprevention due its apoptosis induction capacity and low biotoxicity.     

Effect of phoshpodiesterase 4 (PDE4) inhibibtors on eotaxin expression in humen bronchial epithelial cells

The increasing number of eosinophils into bronchoaelvolar space is observed during noninfectious inflammatory lung diseases. Eotaxins (eotaxin-1/CCL11, eotaxin-2/CCL24, eotaxin-3/CCL26) are the strongest chemotactic agents for eosinophils. Inhibitors of phosphodiesterase 4 (PDE4), the enzyme decomposing cAMP, are anti-inflammatory agents which act through cAMP elevation and inhibit numerous steps of allergic inflammation. The effect of PDE4 inhibitors on eotaxin expression is not known in details. The aim of our study was to evaluate the influence of PDE4 inhibitors: rolipram and RO-20-1724 on expression of eotaxins in bronchial epithelial cell line BEAS-2B. Cells were preincubated with PDE4 inhibitors or dexamethasone for 1 hour and then stimulated with IL-4 or IL-13 alone or in combination with TNF-α. After 48 hours eotaxin protein level was measured by ELISA and mRNA level by real time PCR. Results: PDE4 inhibitors decreased CCL11 and CCL26 expression only in cultures co-stimulated with TNF-α. In cultures stimulated with IL-4 and TNF-α rolipram and RO-20-1724 diminished CCL11 mRNA expression by 34 and 37%, respectively, and CCL26 by 43 and 47%. In cultures stimulated with IL-13 and TNF-α rolipram and RO-20-1724 decreased expression of both eotaxins by about 50%. These results were confirmed at the protein level. The effect of PDE4 inhibitors on eotaxin expression in BEAS-2B cells, in our experimental conditions, depends on TNF-α contribution.     

Data Mining and Bioinformatics of the Expression Data of Esophageal Squamous Cell Carcinoma

The aim is to explore the molecular regulation mechanism of the pathogenesis of the esophageal squamous cell carcinoma. The expression data of esophageal squamous cell carcinoma were obtained from the GEO database. The differential expression genes were identified by the BRB-array tools and the pathway was analyzed by DAVID online tools. The class comparison analysis showed that there were 376 differential expression genes. These genes involved in many tumor-related pathways. What is more, these pathways had common genes. As a conclusion, it was helpful to comprehensively understand the pathogenesis of esophageal squamous carcinoma using data mining and bioinformatics analysis of esophageal squamous cell carcinoma. It would offer new ideas for target therapy of the esophageal squamous cell carcinoma.     

MACC1和C-Met在口腔白斑和口腔鳞状细胞癌中的表达及意义

目的:探讨分析MACC1和C-Met在正常口腔黏膜、口腔白斑及口腔鳞状细胞癌中的表达及其临床意义。方法:采用免疫组化SP法检测20例口腔黏膜、20例上皮异常增生白斑、50例口腔鳞癌组织中的MACC1、C-Met蛋白的表达情况,采用X2和spearman等级相关分析对结果进行判定。结果:MACC1、C-Met蛋白在异常增生型白斑和口腔鳞癌中的阳性表达率分别为50%、76%,35%、66%,均明显高于正常口腔黏膜(17.6%,5.0%),差异均有统计学意义(P0.05)。MACC1和C-Met蛋白表达与口腔鳞癌的分期、淋巴结转移及分化程度密切相关(P0.05)。Spearman等级相关分析显示口腔白斑及口腔鳞癌中MACC1和C-Met的表达呈现正相关(P0.05)。结论:MACC1和C-Met在上皮不典型增生性白斑和口腔鳞癌中高表达,二者在口腔黏膜白斑的癌变和口腔鳞癌的发生发展中可能起重要作用。     

Cloning,stable expression of human phosphodiesterase 7A and development of an assay for screening of PDE7 selective inhibitors

Phosphodiesterases (PDEs) constitute a superfamily of enzymes that plays an important role in signal transduction by catalysing the hydrolysis of cAMP and cGMP. cDNA encoding PDE7A1 subtype was cloned and a stable recombinant HEK 293 cell line expressing high levels of PDE7A1 was generated. Transient transfection of pCRE-Luc plasmid, harboring luciferase reporter gene into the stable recombinant cell line and subsequent treatment with PDE7 inhibitor, resulted in a dose-dependent increase in luciferase activity. This method provides a simple and sensitive cell-based assay for screening of PDE7 selective inhibitors for the treatment of T cell mediated diseases. Renu Malik and Roop Singh Bora contributed equally to this work.     

3-(3-Methoxyphenyl)-6-(3-amino-4-methoxyphenyl)-7H-[1,2,4] triazolo [3,4-b][1,3,4] thiadiazine,a novel tubulin inhibitor,evokes G2/M cell cycle arrest and apoptosis in SGC-7901 and HeLa cells

Gastric cancer and cervical cancer are two major malignant tumors that threaten human health. The novel chemotherapeutic drugs are needed urgently to treat gastric cancer and cervical cancer with high anticancer activity and metabolic stability. Previously we have reported the synthesis, characterization and identification of a novel combretastatin A-4 analog, 3-(3-methoxyphenyl)-6-(3-amino-4- methoxyphenyl) -7H-[1,2,4]triazolo[3,4-b][1,3,4] thiadiazine (XSD-7). In this study, we sought to investigate its anticancer mechanisms in a human gastric cancer cell line (SGC-7901 cells) and human cervical carcinoma cell line (HeLa cells). The 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay showed that XSD-7 induced cytotoxicity in SGC-7901 and HeLa cells with inhibitory concentration 50 values of 0.11 ± 0.03 and 0.12 ± 0.05 µM, respectively. Immunofluorescence studies proved that XSD-7 inhibited microtubule polymerization during cell division in SGC-7901 and HeLa cells. Then, these cells were arrested at G2/M cell cycle and subsequently progressed into apoptosis. In further study, mitochondrial membrane potential analysis and Western blot analysis demonstrated that XSD-7 treatment-induced SGC-7901 cell apoptosis via both the mitochondria-mediated pathway and the death receptor-mediated pathway. In contrast, XSD-7 induced apoptosis in HeLa cells mainly via the mitochondria-mediated pathway. Hence, our data indicate that XSD-7 exerted antiproliferative activity by disrupting microtubule dynamics, leading to cell cycle arrest, and eventually inducing cell apoptosis. XSD-7 with novel structure has the potential to be developed for therapeutic treatment of gastric cancer and cervical cancer.     

Notch1 Is a 5-Fluorouracil Resistant and Poor Survival Marker in Human Esophagus Squamous Cell Carcinomas

Notch signaling involves the processes that govern cell proliferation, cell fate decision, cell differentiation and stem cell maintenance. Due to its fundamental role in stem cells, it has been speculated during the recent years that Notch family may have critical functions in cancer stem cells or cancer cells with a stem cell phenotype, therefore playing an important role in the process of oncogenesis. In this study, expression of Notch family in KYSE70, KYSE140 and KYSE450 squamous esophageal cancer cell lines and virus transformed squamous esophageal epithelial cell line Het-1A was examined by quantitative RT-PCR. Compared to the Het-1A cells, higher levels of Nocth1 and Notch3 expression in the cancer cell lines were identified. Due to the finding that NOTCH3 mainly mediates squamous cell differentiation, NOTCH1 expression was further studied in these cell lines. By Western blot analyses, the KYSE70 cell line which derived from a poorly differentiated tumor highly expressed Notch1, and the Notch1 expression in this cell line was hypoxia inducible, while the KYSE450 cell line which derived from a well differentiated tumor was always negative for Notch1, even in hypoxia. Additional studies demonstrated that the KYSE70 cell line was more 5-FU resistant than the KYSE450 cell line and such 5-FU resistance is correlated to Notch1 expression verified by Notch1 knockdown experiments. In clinical samples, Notch1 protein expression was detected in the basal cells of human esophagus epithelia, and its expression in squamous cell carcinomas was significantly associated with higher pathological grade and shorter overall survival. We conclude that Notch1 expression is associated with cell aggressiveness and 5-FU drug resistance in human esophageal squamous cell carcinoma cell lines in vitro and is significantly associated with a poor survival in human esophageal squamous cell carcinomas.